Influence of extrusion conditions on the colour of millet-legume extrudates using digital imagery

peer-reviewedColour acts as one of the triggers for acceptance of snack foods. Digital imaging in conjunction with Adobe Photoshop can help identification of variations in the colour of extruded products. Response surface methodology-based central composite rotatable designed experiments were conducted to understand the colour components and overall acceptability (OAA) of extruded snacks made from millet–legume blends, 12–28% legume, at different moisture content (MC) of 12–24% wet basis (w.b.), extruded at varying die head temperatures (DHT) from 160–200 °C, barrel temperatures from 100–140 °C and screw speeds of 100–140 rpm. A simple digital camera was used for capturing the images of the extrudates. An L*a*b* colour model (where L* is the black/ white element, a* is green/red and b* is blue/yellow) was used for colour characterisation and OAA was determined by a hedonic scale. It was inferred from the analysis of the resulting statistically valid second order models for the responses that all the colour components were significantly affected by the amount of legume in the extruder feed and by the DHT. It was also observed that DHT, synergistically with other processing parameters, had a significant effect on all the responses. The OAA was highest for the extrudates with higher L* values. Optimum processing conditions were derived while the responses adhered to constraints. The responses of the extrudates prepared under optimum conditions exhibited no significant variation from model predicted values

Spectrum of the non-commutative spherical well

We give precise meaning to piecewise constant potentials in non-commutative quantum mechanics. In particular we discuss the infinite and finite non-commutative spherical well in two dimensions. Using this, bound-states and scattering can be discussed unambiguously. Here we focus on the infinite well and solve for the eigenvalues and eigenfunctions. We find that time reversal symmetry is broken by the non-commutativity. We show that in the commutative and thermodynamic limits the eigenstates and eigenfunctions of the commutative spherical well are recovered and time reversal symmetry is restored

Shapes of Semiflexible Polymers in Confined Spaces

We investigate the conformations of a semiflexible polymer confined to a square box. Results of Monte Carlo simulations show the existence of a shape transition when the persistence length of the polymer becomes comparable to the dimensions of box. An order parameter is introduced to quantify this behavior. A simple mean-field model is constructed to study the effect of the shape transition on the effective persistence length of the polymer.Comment: 8 pages, 20 figure